I have this serializer and model. I want to show in my API the field username of User model, but I receive this error.

AttributeError at /api/v1/client_share_requests/1/

'Profile' object has no attribute 'username'

serializers.py

class ClientShareRequestSerializer(serializers.ModelSerializer):checked_by = serializers.SlugRelatedField(many=True,queryset=Profile.objects.all(),slug_field='username')class Meta:model = ClientShareRequestfields = ('checked_by')

models.py

  class Profile(models.Model):user = models.OneToOneField(User, related_name='profile')class ClientShareRequest(models.Model):checked_by = models.ManyToManyField(Profile, blank=True,related_name='checked_by')

I try to access the User model instance like this:

   checked_by = serializers.SlugRelatedField(many=True,queryset=Profile.objects.all(),slug_field='user.username')

but I receive this error:

'Profile' object has no attribute 'user.username'

Thanks for helping. (Sorry for my English :P)

My guess is DRF does not allow nested attribute lookups on SlugRelatedFields. Simple workaround would be to add a username property on the Profile model and use this in the serializer:

class Profile(models.Model):user = models.OneToOneField(User, related_name='profile')@propertydef username(self): return self.user.usernameclass ClientShareRequest(models.Model):checked_by = models.ManyToManyField(Profile, blank=True,related_name='checked_by')class ClientShareRequestSerializer(serializers.ModelSerializer):checked_by = serializers.SlugRelatedField(many=True,read_only=True,slug_field='username')class Meta:model = ClientShareRequestfields = ('checked_by', )

This works for reads :)